1. Field of the Invention
The present invention relates to a network control apparatus, and in particular to a bandwidth control apparatus in a network such as an Internet service provider which provides an Internet access and an in-enterprise LAN.
In the network control apparatus, a traffic quantity within the network, or with respect to the Internet or the like as a backbone network connected to the outside changes with time as a utilizing status (availability) of user changes. Therefore, it is required to control the bandwidth of the network according to such a change of the traffic quantity.
2. Description of the Related Art
For a bandwidth control in a prior art LAN network control apparatus, as shown in FIG. 7, such control methods have been adopted that a partition (area) is statically set over a whole bandwidth of a transmission line L to secure traffic channels independent of each other, thereby improving a quality of service (QoS), and that a priority for using a bandwidth per user is statically set.
The prior art LAN network control apparatus using the above-mentioned bandwidth control methods performs the bandwidth control by static setting. Therefore, when a file is transferred at one time by a method such as an FTP (File Transfer Protocol), or a plurality of connections are started up, the apparatus can not flexibly deal with a utilizing status of the inside of the LAN network or a backbone changing with time. Accordingly, there has been a problem that a stable quality of service can not be always maintained.
It is accordingly an object of the present invention to provide a network control apparatus which can dynamically control a bandwidth flexibly corresponding to a traffic status of a user.
FIG. 1 shows a schematic arrangement of a network control apparatus according to the present invention. A portion 10 shown by a dotted line indicates an LAN network control apparatus exemplified for a network control apparatus according to the present invention, which is connected to an LAN network 20 connecting terminal equipments 200 such as personal computers and to the Internet 30 as a backbone, e.g. through a router 40.
The LAN network control apparatus 10 comprises a detector 1 for detecting a packet passing through a network and a fact that a whole traffic quantity exceeds a predetermined threshold value, a database DB for holding packet information per user detected by the detector 1, a bandwidth managing portion 2 for detecting a bandwidth occupant based on the information per user in the database DB and for selecting a corresponding bandwidth control method when the detector 1 has detected that the whole traffic quantity has exceeded the predetermined threshold value, and a bandwidth controller 3 for performing a bandwidth control to the bandwidth occupant based on the bandwidth control method selected by the bandwidth managing portion 2.
The arrangement of the present invention shown in FIG. 1 will now be described referring to a schematic diagram of an operation diagram shown in FIG. 2.
In the present invention, the detector 1 firstly detects a packet passing through the network such as a route leading to the LAN network 20 from the Internet 30, and monitors the whole traffic quantity of the network to write the information per user (per-user-information) in the database DB (at step S1).
The detector 1 further determines whether or not the traffic quantity of the whole network exceeds a predetermined threshold value (at step S2).
As a result, when it is found that the whole traffic quantity exceeds the predetermined threshold value, the bandwidth managing portion 2 which has received this notification detects which user occupies the bandwidth referring to a utilizing status table T1 per user (per-user-utilizing status table) and a user order table T2 written in the database DB (at step S3), selects the bandwidth control method corresponding to the user based on a bandwidth control method selection table T3 preliminarily provided in the database DB (at step S4), and notifies the bandwidth controller 3 of the selected method. It is to be noted that xe2x80x9cbandwidth occupationxe2x80x9d includes the status of utilizing a part of the bandwidth of the transmission line.
Receiving the notification from the bandwidth managing portion 2, the bandwidth controller 3 performs the bandwidth control (set/release) (at step S5).
The above-mentioned detector 1 may have a variable value as the predetermined threshold value.
The above-mentioned per-user-utilizing status table T1 may include at least one of an average traffic quantity, an average communication data quantity, an average packet number, an average connection number, and an average session time as a parameter of the per-user-information.
Also, the user order table T2 indicates a ranking (order) of users in respect of each parameter of the per-user-information. The bandwidth managing portion 2 may detect a highest ranking bandwidth occupant at one specified parameter based on the user ranking table T2 (at step S2), determine whether or not the value of another parameter exceeds a corresponding predetermined threshold value by referring to the per-user-utilizing status table T1 when the value of the specified parameter at this time exceeds a corresponding predetermined threshold value, gives points indicating a bandwidth occupation degree when the threshold value is exceeded, and select a bandwidth control method based on the current point from the bandwidth control method selection table T3 (at step S4).
The selection table T3 indicates a correspondence between the point and the bandwidth control method. The bandwidth control method may have contents of the transmission of packet to a partition for a bandwidth occupant and a priority at the time the packet is passed through the partition.
Furthermore, the bandwidth managing portion 2 may use the total value of the above-mentioned points of the parameters.
Moreover, the database DB may have a total point table T4 per user (per-user-total point table) indicating a correspondence between each user and the total point. When the whole traffic quantity is less than the predetermined threshold value after performing the bandwidth control (at step S5), the bandwidth controller 3 may sequentially release the bandwidth control in order from a user with a smaller point, based on the per-user-total point table T4 (at step S5), whereby the bandwidth managing portion 2 may clear the point of the user where bandwidth control is released, from the per-user-total point table T4.
Thus, in this invention, the bandwidth control can be performed according to the whole traffic quantity and the bandwidth availability of the user with a higher traffic quantity, so that it becomes possible to perform a flexible control corresponding to the bandwidth availability changing with time.